[Editor's note: The following contains mild spoilers]Since 2014, CWVerse crossovers have become an annual mainstay on our screens—superheroes from across the CWVerse television shows have been teaming up to take down enemies too powerful to handle on their own.
With the most recent crossover (or crossover-lite) "Armageddon" having concluded and the CWVerse shows returning for the new year, it looks like it’s going to be awhile till the next crossover event takes place. For anyone missing the excitement of crossovers, we take a look at the events that have come before.
We pit the crossover events against one another—judging how monumental the event was, the story, if the characters got their due and how much fun it was. We are only considering crossover events for this piece, and not team-ups (there are too many of those).
9. "Duet"
Kara Danvers/Supergirl (Melissa Benoist) is knocked out by a mysterious alien, so her boyfriend Mon-El (Chris Wood) and father figure J'onn J'onzz/Martian Manhunter (David Harewood) arrive on Earth-1 to seek Barry Allen/the Flash’s (Grant Gustin) help. Soon, the Flash is sucked into the same musical-inspired dreamworld as Kara, and together they must follow a script if they are to make it back home to their loved ones.
‘Duet’ was a musical crossover episode in the third season of The Flash, and it allowed Glee alums, Gustin and Benoist, to show off their singing and dancing talents alongside several supporting cast members and episode guest actor (another Glee breakout star) Darren Criss, all taking turns to steal the show as singing doppelgängers.
But the singing is pretty much the only upside to this crossover. The story is silly and cliché, leaning into old-fashioned romantic tropes to reach a happy ending that undermines the characters’ arcs, especially Supergirl’s. The crossover is still a fun watch on its own and the actors look like they had a whale of a time making it.
8. "Armageddon"
Team Flash are faced with a mysterious new threat at the start of The Flash Season 8 who promises doom for all of Earth. Only Barry Allen can save the world, but who will save Barry… from himself?
"Armageddon" falls into a gray area of crossover events as all five episodes take place on the same show, The Flash, and the main protagonist of the event is Barry Allen. But Barry gets by with a lot of help from his superhero friends, plus, the event appears to have ramifications for characters from across the CWVerse.
"Armageddon" cranks up the emotional tension to the maximum. Team Flash is in tatters and Despero’s (Tony Curran) prophecy tears them further apart. The team also contends with unforeseen circumstances that ratchet up the cracks in their dynamics. But all this anger and conflict feels at odds with these characters. Team Flash always chooses love over war, yet Barry constantly runs headlong into fights instead of talking things through. Even a character like Jefferson Pierce/Black Lightning (Cress Williams), who is from a different show, acts completely out of character. The twists are exciting and infuriating, but Despero comes across as a needling bully, not a villain.
7. "Worlds Finest"
Kara is saved by a mysterious speedster—Barry Allen who arrives on Earth-38 by accident. Barry is quick to help Kara as two villains team up to take revenge on Kara and her boss Cat Grant (Calista Flockhart). Along the way, Kara discovers how to become a better hero and take the risks needed to find love.
If "Worlds Finest" took place today, we’d call it a simple team-up, but back in 2016, the Flash appearing on Supergirl meant Kara and her team were part of the nascent Arrowverse. Instead of being a filler episode, "Worlds Finest" continues Kara’s story while allowing her to team up with another super powered hero. The fact that Kara and Barry hit it off from the get-go plays into their characterizations, especially since Benoist and Gustin have incredible chemistry that makes their partnership work.
The most memorable part of this episode is how non-toxic Barry is. He’s surrounded by women and he’s more than happy to ‘settle this like women’. Barry fits perfectly into Supergirl’s team, and the Superfriends are all the better for it.
6. "Heroes Join Forces"
After Vandal Savage (Casper Crump) tries to kill Kendra Saunders (Ciara Renée), Barry Allen enlists Oliver Queen/Green Arrow’s (Stephen Amell) help to protect her. They soon realize, though, that they’re up against a much mightier villain than they originally presumed. Kendra and Savage’s histories are far more convoluted and Barry and Oliver will need more help—even from their enemies—if they’re to keep everyone safe.
"Heroes Join Forces" was the second crossover event in the Arrowverse (now called the CWVerse) and it seemed like a massive feat at the time since almost every series regular from The Flash and Arrow had a part to play in the event. The crossover also set up the spin-off show DC’s Legends of Tomorrow.
A lot happens in the event beyond just the backdoor pilot of Legends. Oliver uncovers a secret about his past; Team Flash tries to defeat their latest foe. The pacing does feel off at times but the joy of watching Team Flash and Team Arrow partner up is worth it. The tipping point in the episode is a shocking twist that occurs mid-crossover. It’s just as unbelievable when you watch it now as it was back in 2015.
5. Flash vs. Arrow - "The Bold and the Brave"
Oliver, Felicity Smoak (Emily Bett Rickards) and John Diggle (David Ramsey) travel to Central City to investigate a case involving a boomerang. Barry Allen, excited that his friends have come to visit, asks them for help to stop an emotion-controlling meta-human called Rainbow Raider (Paul Anthony). The team-up doesn’t go as planned when Barry and Oliver’s distinct personalities chafe against one another and the battles turn these two friends into enemies.
Barry Allen made his debut on Arrow and the CW show runners ensured that these two characters had a strong bond despite being on two different shows. So, a storyline that pits the two against each other was the perfect idea for the first crossover event in the CWVerse. Both parts of the crossover showcased the differences between the superheroes and how they could overcome them to work better together.
Though the two episodes "Flash vs. Arrow" and "The Brave and the Bold" have separate plot lines and maintain each show’s tone, it doesn’t detract from how thrilling the crossover is. In many ways, the sheer excitement of this event is still palpable.
4. "Crisis on Earth-X"
Barry and Iris West (Candice Patton) are about to commence their wedding when masked villains arrive and disrupt their nuptials. Thankfully the wedding party contains a who’s who of CWVerse superheroes, so they’re able to save the day. The invaders look like Nazis and the heroes soon discover they’re from Earth-X, a world where the Allied Forces lost the Second World War. The superheroes are pulled into a war to save Earth-X, and they get some help from the planet’s resistance cell.
The villains in this crossover are shocking and Earth-X has surprises galore. The crossover leans into the massive CWVerse roster of characters to give fans an ambitious feast. There are character interactions and dynamics that are unanticipated—we’re looking at you, Sara Lance (Caity Lotz) and Alex Danvers (Chyler Leigh)—and portrayals that subvert expectations. This is also the first crossover where the cost of being a superhero is felt by the larger squad. There’s a heartbreaking, yet well-earned farewell to one of the CWVerse’s beloved characters, and it makes the crossover that much more memorable.
The fight scenes are outstanding, especially the first battle at the wedding where superheroes from different shows team up to take down the villains.
3. "Invasion!"
When aliens attack, Barry Allen needs Team Arrow, Supergirl, and the Legends of Tomorrow to stop the invasion! But, while the Dominators are planning world domination, the heroes have their own crisis to deal with—a crisis of trust. Can the heroes overcome their interpersonal conflicts to take down the real villains?
"Invasion!" felt like a real crossover since it included the Legends and Supergirl. Also, extra-terrestrials were now in the mix for the grounded Arrow characters, so this event was completely out of this world. Like its predecessors, "Invasion!" still relied on distinct narratives for each show, and this worked in its favor because the 100th episode of Arrow fell in the middle of the crossover. The episode allowed for a change of pace from the frenetic action and gave fans the chance to see old favorites return for one last hurrah in the episode.
"Invasion!" married the individual storylines of each show with an overarching storyline and lighter tone. The character interactions are the real winner in this crossover especially since many of them meet for the first time. Everyone banding together to stop one of the heroes from sacrificing themselves is still an unforgettable moment in CWVerse history.
2. "Elseworlds"
A mysterious figure hands a powerful book to an Arkham Asylum inmate and the next day The Flash and Green Arrow wake up living each other’s lives. Their teams don’t believe them, so they escape to Earth-38 and get Kara to help. But their troubles have only just started.
DC Comics fans can attest to how exciting "Elseworlds" comics are. They allow one’s imagination to run wild with characters we all love. So, what does an "Elseworlds" take on the CWVerse look like? A lot of fun! Stephen Amell and Grant Gustin look like they are having the time of their lives playing each other’s characters, and later as petty villains. Tyler Hoechlin also gets some scenery-chewing action as Clark Kent/Superman as well as an evil Superman. The "Elseworlds" crossover also introduces viewers to Kate Kane/Batwoman (Ruby Rose) who would go on to headline her own solo show. Kate and Kara’s immediate friendship and chemistry was a welcome addition to the franchise, not to mention a gender-bent nod to the source material.
"Elseworlds" also tied into the subsequent crossover event with decisions made during this event impacting the next. Where this crossover fails is its handling of Supergirl. She’s a passenger throughout the event and doesn’t even get the spotlight in the Supergirl episode. She deserved so much better. But, if you can look beyond that, "Elseworlds" is such a delight to watch.
1. "Crisis on Infinite Earths"
Earths across the multiverse are slowly being destroyed and Supergirl and her Superfriends begin planning an evacuation of Earth-38 to Earth-1. A number of heroes are soon recruited to stop the upcoming crisis. But with shadow demons and the Anti-Monitor (LaMonica Garrett) on their tail, victory is quickly slipping away. Lives will be lost, but will the entire multiverse be lost with it?
We’re all talking about the multiverse nowadays, but not so long ago, the concept of a multiverse had its limitations. And then, "Crisis on Infinite Earths" came along and blew it out of the park. Before Spider-Man: No Way Home there was "Crisis". A multiverse story that had viewers leaping out of their seats with every new reveal. The mind still boggles at what the CW was able to achieve in this epic feast.
From the very first episode in the crossover, the writers threw curveballs at the viewers. The dénouement of the first episode was a bold move, but one that carried weight throughout the story. The anticipation and excitement to see our protagonists meet other incarnations of DC Comics superheroes was unprecedented. And despite the sprawling cast, the writers of "Crisis" still gave the main characters equal weight as well as the chance to grow, to interact and to grieve.
Even now, the impact of "Crisis" is felt by the CWVerse heroes, which is a nice way to remind fans of what a phenomenal event it was.